Conventional pivotal devices are simply connected between a door (window) and a door frame (window frame) so that the door can be maintained at a closed position relative to the door frame. Basically, the pivotal device employs a torsion spring to provide a return force to let the door (window) closes automatically after the door (window) is pivoted away from the frame. However, the door (window) can only be positioned at the closed position so that the door (window) cannot be positioned at 45 degrees or 90 degrees relative to the frame. If the users want to maintain the door (window) at the above mentioned angles, they have to hold the door (window) and cannot release it. This cannot meet requirements of the users because the users may expect the window to be opened and positioned at 45 degrees. Furthermore, the return force of the torsion force could make the door (window) return fast and the quick-return door (window) could hurt the users.
The present invention intends to provide a pivotal device for a door or a window and the pivotal device allows the door or window positioned at various angles relative to the frame. By the pivotal device of the present invention, the users need not to hold the door or the window to maintain it at the desired position.